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Renesas X28HC256WC6721
- Part No.:
- X28HC256WC6721
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- -
- Datasheet:
-
X28HC256WC6721.pdf
- Description:
- IC EEPROM 256KBIT PARALLEL
- Quantity:
- Payment:
- Shipping:
Inventory:2,958
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Product details
Overview
X28HC256WC6721 from Intersil is a 256 kbit (32k × 8) byte-alterable EEPROM operating from a single 5V supply, featuring 90 ns access time, 128-byte page write capability, and JEDEC-standard software data protection. It delivers high reliability via textured poly floating gate technology and supports early write completion detection via DATA polling (I/O7) and Toggle bit (I/O6) for embedded system configuration storage in industrial controllers.
For engineers reviewing the X28HC256WC6721 datasheet, X28HC256WC6721 pinout, X28HC256WC6721 application, or X28HC256WC6721 equivalent, key selection criteria include 5V-only operation, 100,000 write cycles endurance, 100-year data retention, RoHS-compliant SOIC-28 packaging, and compatibility with standard parallel memory bus timing.
Technical Context
The X28HC256WC6721 implements a two-line control architecture using CE and OE for read operations and CE/WE for write operations, eliminating bus contention in multi-device memory arrays. Its internal Direct Write™ cell architecture enables self-timed programming without external high-voltage circuitry or erase-before-write cycles.
It supports both byte and page write modes: page writes load up to 128 consecutive bytes within a 100 µs window before initiating automatic internal programming (~3 ms typical), while status monitoring uses I/O7 complement detection and I/O6 toggling-both compliant with JEDEC-standard early end-of-write signaling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory size | 256 kbit (32,768 × 8) - provides sufficient nonvolatile storage for firmware parameters, calibration tables, and device configuration in resource-constrained systems. |
| Access time | 90 ns - enables direct interfacing with legacy 8-bit microcontrollers (e.g., 8051, Z80) running at ≤10 MHz without wait states. |
| Write endurance | 100,000 cycles per byte - ensures long-term field reliability for applications requiring frequent parameter updates, such as programmable logic controllers. |
| Data retention | 100 years at +25°C - guarantees data integrity over full product lifecycle without battery backup or refresh mechanisms. |
| Supply voltage | 5 V ±10% - simplifies power design by eliminating need for dedicated programming voltage rails or level shifters. |
| Operating temperature | -40°C to +85°C - qualified for industrial-grade deployment in factory automation, motor drives, and outdoor metering equipment. |
| Page write size | 128 bytes - reduces total write time for bulk updates (e.g., full configuration save) to <0.8 s, minimizing system downtime during reprogramming. |
Pinout & Package
Package: 28-lead SOIC (300-mil, RoHS-compliant, MDP0027 footprint). Pin count and physical layout match JEDEC MS-013-AE standard.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address inputs | 15-bit address bus selects one of 32,768 bytes; A7–A14 define page address for 128-byte page writes. |
| I/O0–I/O7 | Bi-directional data bus | Transfers data during reads/writes; I/O7 provides DATA polling status, I/O6 provides Toggle bit status. |
| CE | Chip Enable | Active-low primary device select; when HIGH, places device in low-power standby (500 µA max). |
| OE | Output Enable | Active-low read control; used with CE to enable output buffers and prevent bus contention. |
| WE | Write Enable | Active-low write control; latches data on rising edge (with CE) and initiates internal programming cycle. |
| VCC / VSS | Power / Ground | Single 5V supply; decoupling requires 0.1 µF ceramic capacitor per device plus 4.7 µF bulk cap per 8 devices. |
Key Features
| Feature | Design Value |
|---|---|
| Direct Write™ cell technology | Enables 5V-only operation with no external high-voltage generator, reducing BOM cost and PCB area. |
| 128-byte page write | Reduces average write time per byte to 24 µs, accelerating full-memory rewrites by >10× versus sequential byte writes. |
| DATA polling (I/O7) | Allows host CPU to poll completion status without interrupts or timers, simplifying firmware implementation in bare-metal systems. |
| Toggle bit (I/O6) | Eliminates need to store last written address/data for polling, enabling efficient multi-device array updates. |
| JEDEC software data protection | Prevents inadvertent writes during power-up/down via 3-byte unlock sequence; nonvolatile until reset command issued. |
Applications
| Industrial PLC Configuration Storage | Medical Device Calibration Data Retention |
|---|---|
Use Scenario: Storing user-defined I/O mapping, PID tuning parameters, and alarm thresholds in programmable logic controllers deployed in harsh factory environments. IC Role / Device Role / Timing Role: Nonvolatile configuration register providing byte-level random access and guaranteed 100-year data retention without battery support. Use Value: Eliminates need for supercapacitors or backup batteries, reducing maintenance cost and improving long-term reliability in unattended operation. |
Use Scenario: Preserving sensor calibration coefficients, usage logs, and regulatory audit trails in portable diagnostic equipment subject to frequent power cycling. IC Role / Device Role / Timing Role: Secure, tamper-resistant parameter store with software lockout preventing accidental overwrite during boot or firmware update. Use Value: Ensures traceability and compliance with IEC 62304 requirements by maintaining immutable calibration history across device lifetimes. |
| Automotive Body Control Module Settings | Telecom Equipment Bootloader Parameters |
Use Scenario: Holding seat/mirror position presets, lighting profiles, and door lock behavior in automotive BCMs operating across -40°C to +85°C ambient range. IC Role / Device Role / Timing Role: Industrial-temperature EEPROM interfaced directly to 8-bit MCU via parallel bus, supporting fast page writes during vehicle personalization. Use Value: Enables zero-latency recall of user preferences after ignition cycle, meeting OEM responsiveness requirements (<500 ms). |
Use Scenario: Storing MAC addresses, firmware version stamps, and hardware revision IDs in network switches and base station radios requiring field-upgradable configurations. IC Role / Device Role / Timing Role: System-critical identity register accessed during boot ROM initialization; supports concurrent read/write via CE/OE/WE control lines. Use Value: Prevents configuration loss during hot-swap events or brownout conditions using hardware VCC sense and write-inhibit logic. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT28C256-15PU | 150 ns access time; 5V-only; same 32k×8 organization; 100,000-cycle endurance; PDIP-28 package only. | Lacks page write mode - requires individual byte writes, increasing full-memory rewrite time to >3 seconds. | Select when legacy through-hole assembly is required and timing budget allows slower access. |
| MX28LV256A-90PC | 90 ns access; 3.3V/5V dual-voltage support; 128-byte page write; SOIC-28; 100,000-cycle endurance. | Requires VCC = 3.3V or 5V selection via external strap; not pin-compatible due to different pin 1 marking and internal VCC detect logic. | Select for mixed-voltage systems where future migration to 3.3V operation is planned. |
Compared with AT28C256-15PU and MX28LV256A-90PC, the X28HC256WC6721 offers identical 90 ns speed and SOIC-28 packaging but uniquely combines JEDEC software protection, robust 5V-only operation, and guaranteed 100-year retention - making it optimal for industrial designs prioritizing long-term data integrity and simplified firmware polling.
Availability
X28HC256WC6721 is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostics equipment, automotive body control modules, and telecom infrastructure requiring stable component supply with guaranteed 100-year data retention and 100,000 write-cycle endurance.
Supply support for X28HC256WC6721 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Intersil Corporation is a leading provider of precision analog and power management solutions, serving industrial, infrastructure, and high-end consumer markets with high-reliability semiconductor products.
The X28HC256WC6721 belongs to Intersil's second-generation CMOS EEPROM product line, designed specifically for industrial and automotive applications demanding robust 5V-only nonvolatile storage with advanced write-protection and long-term data integrity.
FAQ
What is the maximum write speed achievable with X28HC256WC6721?
The X28HC256WC6721 achieves an effective write speed of 24 µs per byte using its 128-byte page write mode, enabling full 256 kbit memory rewrite in under 0.8 seconds. Individual byte writes require ~3 ms per byte, but page mode eliminates inter-byte delays by allowing up to 127 subsequent writes within a 100 µs window after the first WE pulse.
Does X28HC256WC6721 require external high-voltage circuitry for programming?
No, the X28HC256WC6721 operates from a single 5V supply and requires no external high-voltage generators, VP-P control circuits, or complex programming algorithms. Its textured poly floating gate technology enables Direct Write™ functionality, making it compatible with standard 5V microcontroller buses without level-shifting components.
How does software data protection work on X28HC256WC6721?
X28HC256WC6721 implements JEDEC-standard software data protection via a three-byte unlock sequence (AAh to 5555h, 55h to 2AAAh, A0h to 5555h) that must precede any write operation once enabled. The protection remains active across power cycles and prevents inadvertent writes during power-up/down unless the sequence is repeated.
Can X28HC256WC6721 be used in systems with mixed 3.3V and 5V logic?
The X28HC256WC6721 is strictly a 5V-only device (VCC = 5V ±10%) and is not rated for 3.3V operation. Its input thresholds (VIH ≥2V, VIL ≤0.8V) allow interface with 3.3V logic outputs when pulled up to 5V, but all control signals (CE, OE, WE) and I/O lines must be driven within 5V TTL levels to ensure reliable operation and avoid latch-up.
What is the significance of the "W" in X28HC256WC6721?
The "W" in X28HC256WC6721 denotes the industrial temperature grade (-40°C to +85°C), while "C6721" indicates the specific SOIC-28 package variant with RoHS-compliant matte tin plating (e3 termination), 300-mil body width, and MDP0027 footprint - matching JEDEC MS-013-AE standard for automated assembly.
X28HC256WC6721 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- -
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- EEPROM
- Technology:
- EEPROM
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 5ms
- Access Time:
- -
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
X28HC256WC6721 FAQ
1.How can I place an order for X28HC256WC6721 through Aetrix?
Please submit a Request for Quotation (RFQ) for X28HC256WC6721 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for X28HC256WC6721 reliable?
The price and inventory of X28HC256WC6721 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for X28HC256WC6721 is usually 5 days.
3.What payment methods are accepted for X28HC256WC6721?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for X28HC256WC6721 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for X28HC256WC6721?
X28HC256WC6721 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your X28HC256WC6721 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for X28HC256WC6721?
For technical support, including X28HC256WC6721 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your X28HC256WC6721 requirements.
6.How does Aetrix verify that X28HC256WC6721 is sourced from the original manufacturer or authorized distributors?
All X28HC256WC6721 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that X28HC256WC6721 meets industry standards.
7.What is the process for return or replacement of X28HC256WC6721?
All X28HC256WC6721 units undergo pre-shipment inspection (PSI). If there is an issue with X28HC256WC6721, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The X28HC256WC6721 part is unused and in its original packaging.
Return procedure for X28HC256WC6721:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
X28HC256WC6721 Tags
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